Safety device for vehicle seats

ABSTRACT

The invention relates to a safety device ( 1 ) for a vehicle seat which is fixed inside a vehicle by means of lateral guides. Said safety device consists of at least one safety rail ( 8 ) which is to be fixed in the vehicle, in the region between the guides, and comprises associated safety means ( 10 ) which are connected to, or are to be connected to, the vehicle seat, and co-operate with the safety rail ( 8 ) in such a way that they ( 10 ) are arranged in a non-contact manner in relation thereto ( 8 ) for regular loads applied to the seat, and in the event of irregular, especially accident-related deformations and/or movements in the region of the vehicle seat, engage with the safety rail ( 8 ) in such a way that they block further deformations/displacements. The safety means ( 10 ) and the safety rail ( 8 ) are embodied in such a way that, during the engagement, reaction forces which act in the direction of axes (X, Y, Z) of a standard vehicle co-ordinates system are applied in a distributed manner to at least two different engagement regions of the safety rail ( 8 ).

The present invention relates to a safety device for a vehicle seatsecured within a vehicle via lateral guides, said device comprising atleast one securing rail which is to be arranged in a positionally fixedmanner in the floor region of the vehicle in the region between theguides and has associated securing means, which are connected or are tobe connected to the vehicle seat and interact with the securing rail insuch a manner that, in the case of regular seat loads, the securingmeans are arranged in a contactless manner relative to the securing railand, by means of irregular, in particular accident-related deformationsand/or movements in the region of the vehicle seat, come into engagementwith the securing rail locking the vehicle seat against furtherdeformations/movements.

A safety device of this type is described, for example, in WO 00/27667.This known device is provided for a multiple seat, i.e. a seat bench,which can be displaced over a region of adjustment via two lateral,parallel sliding guides within the vehicle and is guided in a mannersuch that it can be locked in different positions. In the event ofsevere decelerations and, in particular, in the case of accidents(head-on and rear impacts), the seat or the seat bench are subjected tolarge reaction forces which may be of such magnitude that without asafety device deformations of the entire seat bench or its supportingstructure and, furthermore, also deformations in the region of thelateral guides and, in the worst case scenario, the entire seatarrangement could even be torn out. This is avoided by the safety deviceby the securing rail being arranged between the lateral seat slidingguides and parallel thereto, the securing means, which are designed as asecuring slide, being arranged in a freely moveable mannerlongitudinally relative to the securing rail during regular displacementmovements and in positions within the region of adjustment of the seatbench, but, by means of irregular deformations, which occur in the caseof severe, for example accident-related decelerations or accelerations,in the region of the seat bench coming into engagement with the securingrail locking the seat bench. In the case of the known safety device,this engagement takes place in the region of lateral retaining webs withthe securing rail, which is of approximately U-shaped design and is openupward, with, as the locking means, a plurality of cutouts distributedover the length of the rail being provided in the region of theretaining webs for engagement of at least one locking element of thesecuring slide. The supporting of the reaction forces therefore takesplace here exclusively in the upper end region of the retaining webs ofthe securing rail. Thus, in the case of the known embodiment, thesecuring rail has to be very robust and consequently of a large size inorder to be able to support the forces, which occur in a concentratedmanner at one point.

The present invention is based on the object of improving a safetydevice of the type mentioned in such a manner that the components can besignificantly lighter and smaller in size while an effective securingfunction is maintained.

According to the invention, this is achieved by the securing means andthe securing rail being designed in such a manner that, during theengagement, deceleration-related reaction forces, which act in thedirection of axes of a conventional vehicle coordinate system, areabsorbed in at least two different engagement regions of the securingrail. A distribution of the reaction forces to different engagementregions is therefore achieved according to the invention. This conceptis based on the finding that up to approximately 40% of the reactionforces occurring in most cases act in the direction of a horizontalvehicle longitudinal axis (X-axis of the conventional vehicle coordinatesystem) and up to approximately 60% of them act in the direction of avertical axis (Z-axis) and possibly in the direction of a horizontaltransverse axis (Y-axis). The securing means therefore have, in oneadvantageous refinement of the invention, a first engagement part forabsorbing forces primarily in the direction of the vertical axis (Z)and, if appropriate, also in the direction of the transverse axis (Y),and a separate, second engagement part for absorbing forces primarilyacting in the direction of the longitudinal axis (X). In thisconnection, provision is made, in a particularly advantageousrefinement, for the second engagement part to be movable relative to thefirst engagement part in such a manner that, by a certain actuatingforce being applied to it, it can be moved from a non-engagementposition into an engagement position also independently of the firstengagement part and, in particular, already before the latter in time.This results in the further advantage of being able to use a seatbelttensile force as actuating force by the second engagement part beingconnected, for actuation purposes, to a seatbelt securing means (inparticular to a belt buckle in the seat region). A control activated bythe belt force thereby enables the forces acting in the direction of thelongitudinal axis to be supported even before deformations occur in theregion of the seat structure that then give rise to forces acting, inparticular, in the direction of the vertical axis.

The force distribution according to the invention in particular enablesthe securing rail to be significantly lighter and of a smaller size. Inone embodiment, in which the securing rail has a U- or horizontallyC-shaped cross section open upward in the direction of the seat for theengagement of the securing means and with a base and two retaining limbsbounding a longitudinal opening, the invention provides locking means inthe region of the base, in particular in the form of a plurality oftoothing-like cutouts distributed in the longitudinal direction of therail, for engagement of a pawl-like locking section of the secondengagement part. Analogously to the prior art, the first engagement partuses supporting sections to engage behind the retaining limbs of thesecuring rail, but, because of the invention, forces are only absorbedhere in the direction of the vertical axis and, if appropriate, in thedirection of the transverse axis.

Further advantageous refinement features of the invention are containedin the subclaims and in the following description.

The invention is to be explained in more precise detail with referenceto preferred exemplary embodiments which are illustrated in the drawing,in which:

FIG. 1 shows a first embodiment of a safety device according to theinvention in a perspective view obliquely from the front and top,

FIG. 2 shows a perspective view obliquely from the rear,

FIG. 3 shows a further perspective view partially broken open to showthe securing means,

FIG. 4 shows a longitudinal section through the safety device in thestarting position (non-engagement position)

FIG. 5 shows a view as in FIG. 4, but in the engagement position,

FIG. 6 shows an enlarged cross section in the plane VI-VI according toFIG. 4,

FIG. 7 shows a cross section in the plane VII-VII according to FIG. 4,

FIG. 8 shows a second embodiment of the safety device according to theinvention in a perspective view obliquely from the rear,

FIG. 9 shows a longitudinal section through the embodiment according toFIG. 8 (section plane IX-IX in FIG. 10), and

FIG. 10 shows an enlarged cross section in the plane X-X according toFIG. 9.

In the various figures of the drawing, parts and components which areidentical or correspond functionally are always provided with the samereference numbers, and so they generally also only need to be describedonce in each case.

In the figures of the drawing, of a vehicle seat which is to be securedby a safety device 1 according to the invention, which seat may also bedesigned as a multiple seat or seat bench, only a supporting seatstructure or a seat frame 2 together with one of a number ofcrossmembers 4 and one of a number of longitudinal members 6 isindicated. The vehicle seat or its seat frame 2 can be displaced over acertain region of adjustment in the longitudinal direction of thevehicle (X-axis of a conventional vehicle coordinate system) via twolateral sliding guides (not illustrated) parallel to each other within avehicle and, in this connection, can be guided in a manner such that itcan be locked in different positions.

The safety device 1 comprises essentially (at least) one securing rail 8which is to be arranged in the floor region of the vehicle in apositionally fixed manner in the region between the seat guides andparallel to the direction of displacement of the seat and has associatedsecuring means 10, which are connected or are to be connected to thevehicle seat or the seat frame 2 and interact with the securing rail 8in such a manner that, in the case of regular seat loads, the securingmeans 10 are arranged contactlessly relative to the securing rail 8 and,as a result, in a freely movable manner longitudinally within theadjustment region of the seat but, by means of irregular, in particularaccident-related deformation and/or movements in the region of thevehicle seat or of the seat frame 2, come into engagement with thesecuring rail 8 locking the seat against further deformations and/ormovements.

According to the invention, the securing means 10 and the securing rail8 are designed in such a manner that, during the engagement of thesecuring means 10, reaction forces produced via the seat are absorbed inat least two different engagement regions of the securing rail 8.

In the exemplary embodiments illustrated, the securing rail 8 has anapproximately U- or horizontally C-shaped cross section which is openupward in the direction of the seat for engagement of the securing means10 with a base 12 and two retaining limbs 16 bounding a slot-shapedlongitudinal opening 14. The retaining limbs 16 are expediently bentover inward through approximately 180° in the upper, free end region soas to form supporting edges 18.

In this embodiment, reaction forces, which act in the direction of ahorizontal longitudinal axis X of a conventional vehicle coordinatesystem, which is shown in FIGS. 1, 3 and 8 and also partially in FIGS. 4and 5, are preferably absorbed in an engagement region formed by thebase 12. A further engagement region is formed by the retaining limbs orthe supporting edges 18, to be precise primarily for reaction forceswhich act in the direction of a vertical axis Z and, if appropriate,also in the direction of a horizontal transverse axis Y.

For this purpose, the securing means 10 have a first engagement part 20for absorbing the forces primarily in the Z- and Y-direction andfurthermore a separate, second engagement part 22 for absorbing theforce primarily in the direction of longitudinal axis X. The firstengagement part 20 is connected rigidly to the seat frame 2 in such amanner that only deformations or movements occurring in the region ofthe seat frame 2 cause it to come into an engagement position in theregion of the supporting edges 18 of the retaining limbs 16 of thesecuring rail 8. By contrast, the second engagement part 22 can bemoved, according to the invention, relative to the first engagement part20 in such a manner that, by a certain actuating force F being appliedto it, it can be moved from a non-engagement position into an engagementposition in the region of the base 12 of the securing rail 8 alsoindependently of the first engagement part 20, i.e. in particular, alsoalready before the latter in time.

In one particularly advantageous refinement of the invention, the secondengagement part 22 is connected to a seatbelt securing means (notillustrated) in such a manner that a belt tensile force acts on thesecond engagement part 22 as actuating force F. The effectadvantageously achieved as a result is that the engagement for thepurpose of supporting the reaction forces primarily acting in theX-direction is activated by the belt tensile force (“securing activatedby belt force”).

In this connection, it is furthermore advantageous if, in its engagementposition, the second engagement part 22 additionally also usessupporting sections 24 to absorb forces in the direction of the verticalaxis Z and, if appropriate, in the direction of the transverse axis Y,but with the supporting sections 24 coming into engagement in the regionof the supporting edges 18 of the retaining limbs 16 of the securingrail 8.

The first engagement part 20 likewise uses supporting sections 26 toengage behind the retaining limbs 16 or the supporting edges 18 thereofto support the forces in the Z/Y direction.

The securing rail 8 has locking means in the region of the base 12, inparticular in the form of a plurality of toothing-like cutouts 28distributed in the longitudinal direction of the rail, for form-fittingengagement of a pawl-like locking section 30 of the second engagementpart 22. The forces acting in the X-direction are therefore supportedvia the webs 32 formed in each case between the cutouts 28. The lockingsection 30 can have—as illustrated—(at least) two engagement lugs 30 afor the simultaneous engagement, in a form-fitting manner in theX-direction, in two cutouts 28.

In the preferred exemplary embodiments illustrated, the secondengagement part 22 is designed as a double lever mounted pivotably abouta transverse axis by means of a hinge bolt 34. In this case, a firstlever section 36 can have the actuating force F applied to it, and asecond lever section 38 has the locking section 30 for engagement in theregion of the base 12 of the securing rail 8. The first lever section 36also has the supporting sections 24 for engaging behind the retaininglimbs 16 of the securing rail 8 (see, for example, FIG. 3). The secondengagement part 22 is expediently locked in its non-engagement positionin such a manner that an unlocking for transferring it into theengagement position is possible only by means of an actuating force Fexceeding a certain minimum value. This advantageously avoids evenrelatively small belt forces, for example breaking-related forces, beingable to lead to unlocking and engagement occurring. The secondengagement part 22 is preferably locked in the non-engagement positionby a predetermined breaking point, in particular in the form of aninterchangeable shearing pin 40. This predetermined breaking point orthe shearing pin 40 is configured in such a manner that breaking occursonly above a certain value of the actuating force F.

Some differences in the two embodiments illustrated, on the one hand, inFIGS. 1 to 7 and, on the other hand, in FIGS. 8 to 10 will be explainedbelow.

According to FIGS. 1 to 7, the first engagement part 20 is fastened, inparticular welded, to a rear frame transverse member 4 in such a mannerthat it protrudes freely from the transverse member into the region ofthe securing rail 8. In this case, the first engagement part 20expediently comprises two flat parts which are parallel to each otherand between them form a mount for the pivoting mounting of the second,lever-shaped engagement part 22. In this respect, the hinge bolt 34extends through aligned openings of the two engagement parts. The sameis also true for the shearing pin 40. As emerges in this connection inparticular from FIGS. 3 to 5, the supporting sections 24 and 26 of thetwo engagement parts 20, 22, which sections are provided for engagingbehind the supporting edges 18 of the retaining limbs 16 of the securingrail 8, are expediently offset with respect to each other in thelongitudinal direction of the securing rail 8. This results in theadvantage of a very low overall height for the securing rail 8.

As far as the variant embodiment according to FIGS. 8 to 10 isconcerned, the first engagement part 20 is formed here as an integralpart of a frame longitudinal member 8. In this connection, the secondengagement part 22 comprises two flat parts which are arranged on bothsides of the longitudinal member 6. The two flat parts of the secondengagement part 22 therefore accommodate the first engagement part 20between them. In this case too, the hinge bolt 34 and the shearing pin40 extend in each case through aligned openings of the two engagementparts 20, 22. According to the cross section in FIG. 10, in this casethe supporting sections 24, 26 of the two engagement parts 20, 22 arearranged together in a region of the longitudinal extent of the securingrail 8. The supporting sections 26 of the first engagement part 20preferably engage behind the retaining limbs 16 indirectly by engagingunder the supporting sections 24 of the second engagement part 22.However, this leads to a somewhat larger overall height for thearrangement.

The invention is not confined to the exemplary embodiments illustratedand described, but also encompasses all embodiments of equivalent effectwithin the meaning of the invention. Furthermore, the invention is alsonot yet confined to the combination of features defined in claim 1 butmay also be defined by any other desired combination of particularfeatures of all disclosed individual features. This means that, inprinciple, virtually any individual feature of claim 1 can be omitted orreplaced by at least one individual feature disclosed elsewhere in theapplication. To this extent, claim 1 is to be understood merely as afirst attempt at formulating an invention.

1. A safety device (1) for a vehicle seat to be secured within a vehicle via lateral guides, the safety device comprising at least one securing rail (8) which is to be arranged in the vehicle in a positionally fixed manner in the region between the lateral guides and having associated securing mechanisms (10), to be connected to the vehicle seat and interact with the securing rail (8) in such a manner that, in the case of regular seat loads, the securing mechanisms (10) are arranged in a contactless manner relative to the securing rail (8) and, by means of irregular, in particular accident-related deformations and/or movements in the region of the vehicle seat, come into engagement with the securing rail (8) locking the vehicle seat against further deformations/movements, wherein the securing mechanisms (10) and the securing rail (8) are designed in such a manner that, during the engagement, reaction forces, which act in the direction of axes (X, Y, Z) of a conventional vehicle coordinate system, are absorbed in a manner distributed to at least two different engagement regions of the securing rail (8).
 2. The safety device as claimed in claim 1, wherein the securing mechanisms (10) have a first engagement part (20) for absorbing forces primarily in the direction of a vertical axis (Z) and, if appropriate, in the direction of a horizontal vehicle transverse axis (Y), and a second engagement part (22) for absorbing force primarily in the direction of a horizontal vehicle longitudinal axis (X).
 3. The safety device as claimed in claim 2, wherein the first engagement part (20) is connected rigidly to a seat frame (2) in such a manner that deformations or movements occurring in the region of the seat frame (2) cause it to come into an engagement position with the securing rail (8).
 4. The safety device as claimed in claim 2, wherein the second engagement part (22) can be moved relative to the first engagement part (20) in such manner that, by a certain actuating force (F) being applied to it, it can be moved from a non-engagement position into an engagement position also independently of the first engagement part (20).
 5. The safety device as claimed in claim 4, wherein the second engagement part (22) is connected to a seatbelt securing device in such a manner that a belt tensile force acts on the second engagement part (22) as actuating force (F).
 6. The safety device as claimed in claim 2, wherein, in its engagement position, the second engagement part (22) also uses supporting sections (24) to absorb forces in the direction of the vertical axis (Z) and the transverse axis (Y).
 7. The safety device as claimed in claim 1, wherein the securing rail (8) has an approximately U-shaped cross section which is open upward in the direction of the seat for the engagement of the securing mechanisms (10) with a base (12) and two retaining limbs (16) bounding a longitudinal opening (14).
 8. The safety device as claimed in claim 7, wherein the first engagement part (20) of the securing mechanisms (10) uses supporting sections (26) to engage behind the retaining limbs (16) of the securing rail (8).
 9. The safety device as claimed in claim 7, wherein the securing rail (8) has locking means in the region of the base (12), in particular in the form of a plurality of toothed cutouts (28) distributed in the longitudinal direction of the rail, for engagement of a locking section (30) of the second engagement part (22).
 10. The safety device as claimed in claim 4, wherein the second engagement part (22) is designed as a double lever mounted pivotably about a transverse axis, a first lever section (36) having the actuating force (F) applied to it, and a second lever section (38) serving for engagement in the securing rail (8).
 11. The safety device as claimed in claim 4, wherein the second engagement part (22) is locked in its non-engagement position in such a manner that an unlocking for transferring it into the engagement position takes place only by an actuating force (F) exceeding a certain minimum value.
 12. The safety device as claimed in claim 11, wherein the second engagement part (22) is locked by a predetermined breaking point utilizing a shearing pin (40).
 13. The safety device as claimed in claim 6, wherein the supporting sections (24, 26) of the first and second engagement parts (20, 22), which sections are provided for engaging behind the retaining limbs (16) of the securing rail (8), are offset with respect to each other in the longitudinal direction of the securing rail (8).
 14. The safety device as claimed in claim 6, wherein the supporting sections (24, 26) of the first and second engagement parts (20, 22), which sections are provided for engaging behind the retaining limbs (16) of the securing rail (8), are arranged together in a region of the longitudinal extent of the securing rail (8), the supporting sections (26) of the first engagement part (20) engaging behind the retaining limbs (16) of the securing rail (8) indirectly via the supporting sections (24) of the second engagement part (22).
 15. The safety device as claimed in claim 2, wherein the first engagement part (20) is an integral part of a frame longitudinal member (6) of the vehicle seat.
 16. The safety device as claimed in claim 2, wherein the first engagement part (20) is fastened to a frame transverse member (4) of the vehicle seat and protrudes freely from the transverse member (4) into the region of the securing rail (8).
 17. A safety device (1) for a vehicle seat to be secured within a vehicle via lateral guides, the safety device comprising at least one securing rail (8) which is to be arranged in the vehicle in a positionally fixed manner in the region between the lateral guides and having associated securing mechanisms (10), to be connected to the vehicle seat and interact with the securing rail (8) in such a manner that, in the case of regular seat loads, the securing mechanisms (10) are arranged in a contactless manner relative to the securing rail (8) and, by means of irregular, in particular accident-related deformations and/or movements in the region of the vehicle seat, come into engagement with the securing rail (8) locking the vehicle seat against further deformations/movements, wherein the securing mechanisms (10) and the securing rail (8) are designed in such a manner that, during the engagement, reaction forces, which act in the direction of axes (X, Y, Z) of a conventional vehicle coordinate system, are absorbed in a manner distributed to at least two different engagement regions of the securing rail (8); and wherein the securing mechanisms (10) have a first engagement part (20) for absorbing forces primarily in the direction of a vertical axis (Z), the first engagement part (20) is an integral part of a frame longitudinal member (6) of the vehicle seat.
 18. A safety device (1) for a vehicle seat to be secured within a vehicle via lateral guides, the safety device comprising at least one securing rail (8) which is to be arranged in the vehicle in a positionally fixed manner in the region between the lateral guides and having associated securing mechanisms (10), to be connected to the vehicle seat and interact with the securing rail (8) in such a manner that, in the case of regular seat loads, the securing mechanisms (10) are arranged in a contactless manner relative to the securing rail (8) and, by means of irregular, in particular accident-related deformations and/or movements in the region of the vehicle seat, come into engagement with the securing rail (8) locking the vehicle seat against further deformations/movements, wherein the securing mechanisms (10) and the securing rail (8) are designed in such a manner that, during the engagement, reaction forces, which act in the direction of axes (X, Y, Z) of a conventional vehicle coordinate system, are absorbed in a manner distributed to at least two different engagement regions of the securing rail (8); and wherein the securing mechanisms (10) have a first engagement part (20) for absorbing forces primarily in the direction of a horizontal vehicle transverse axis (Y). 